Using Win10x64. Thanks for the link, but bluetooth itself is not a problem. The lappy is paired with the Bose speaker and connects to it easily. When I use BiaB with ASIO4ALL (which admittedly is not a true ASIO driver, but a WDM wrapper), ASIO4ALL sees the Bose as an output option and BiaB uses it. The problem there is latency of the keyboard controller when I play along with a BiaB song.

So I'm thinking a usb audio interface will solve that latency issue. At moment, I wouldn't care about the I/O on the interface if I could get it's output to the bluetooth speaker.

What I wasn't clear about is whether the (true) ASIO driver for, say the Scarlett, will offer the bluetooth speaker as an option. Since it'd be a dedicated driver, it appears the answer is no. Darn it.